Amberlite IR-120陽離子交換樹脂於游離脂肪酸甲酯化之研究

Abstract

Biodiesel, a mixture of fatty esters, has become more and more important as an alternative diesel fuel, since it is made from renewable sources and possesses biodegradability, nontoxicity and reusability. In general, biodiesel is produced from transesterification and esterification of oils and fatty acids with alcohols of low molecular weight over adequate catalysts. Among all catalysts, alkaline catalysts cannot be properly used in those oils with high free-fatty-acid (FFA) content as well as moisture due to saponification. In contrast, homogeneous acidic catalysts are commonly used to catalyze esterification of free fatty acids with alcohols. However, it is corrosive and very difficult to remove excess acid from product. Heterogeneous acidic catalysts can overcome this problem. In this study, the cation-exchange resin - Amberlite IR-120 as a catalyst has been studied in catalytic esterification of palmitic acid with methanol. Effects of various parameters such as reaction temperature, catalyst loading, molar ratio of alcohol to oil, and reaction time have been carefully investigated. Reacting at 60 C, 600 rpm, methanol-to-fatty acid ratio at 6:1 and 20 wt% catalyst, it could reach a conversion of 90.98%. In this dissertation, we also discuss the effect of water on Amberlite IR-120’s catalytic esterification, which shows water could inhibit esterification both in one phase and two phase system.